18021018 has 16 divisors (see below), whose sum is σ = 36085536. Its totient is φ = 5999760.

The previous prime is 18020993. The next prime is 18021053. The reversal of 18021018 is 81012081.

It is a junction number, because it is equal to n+sod(n) for n = 18020985 and 18021003.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6528 + ... + 8868.

It is an arithmetic number, because the mean of its divisors is an integer number (2255346).

Almost surely, 2^18021018 is an apocalyptic number.

18021018 is an abundant number, since it is smaller than the sum of its proper divisors (18064518).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18021018 is a wasteful number, since it uses less digits than its factorization.

18021018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3629.

The product of its (nonzero) digits is 128, while the sum is 21.

The square root of 18021018 is about 4245.1169595195. The cubic root of 18021018 is about 262.1761048229.

Adding to 18021018 its reverse (81012081), we get a palindrome (99033099).

The spelling of 18021018 in words is "eighteen million, twenty-one thousand, eighteen".